It would be alot of proof that the XX1 works.. (even though im running it and have never lost a chain...) i think it would be cool if the pros stood behind there sponsors product.
XX1 works fine, but downhill courses are just too hard on drivetrains. An XX1 ring would not keep the chain on during any sort of riding that requires a DH bike. For enduro/am/trail/XC it works great though.